Allergic Diseases and Risk of Malignancy of Gastrointestinal Cancers

Mendelian randomization analysis of atopic dermatitis and esophageal cancer in East Asian and European populations

Background

Emerging observational studies showed an association between atopic dermatitis (AD) and gastrointestinal cancers. However, it remains unclear whether this association is causal, particularly in the case of cancers like esophageal cancer, which exhibit ancestral genetic traits.

Methods

To assess the potential causal relationship between AD and esophageal cancer across diverse ancestral backgrounds, we conducted a 2-sample Mendelian randomization study. Independent genetic instruments for AD from the FinnGen consortium (N case = 7024 and N control = 198 740), BioBank Japan (N case = 2385 and N control = 209 651) and Early Genetics and Lifecourse Epidemiology (EAGLE) eczema consortium (N case = 18 900 and N control = 84 166, without the 23andMe study) were used to investigate the association with esophageal cancer in the UK Biobank study (N case = 740 and N control = 372 016) and BioBank Japan esophageal cancer sample (N case = 1300 and N control = 197 045).

Results

When esophageal cancer extracted from East Asian ancestry was used as a outcome factor, AD data extracted from BioBank Japan (OR = 0.90, 95% CI: 0.83-0.98), FinnGen consortium (OR = 0.86, 95% CI: 0.77-0.96), and EAGLE consortium (OR = 0.92, 95% CI: 0.81-1.06) were negatively associated with esophageal cancer susceptibility. However, AD as a whole did not show an association with esophageal cancer from European ancestry.

Conclusion

This study provides support for a causal relationship between AD and esophageal cancer in East Asian populations but not between AD and esophageal cancer from European ancestry. The specific associations between esophageal cancer and AD appear to exhibit significant disparities between the East Asian and European regions.

Causal relationship between lung diseases and risk of esophageal cancer: insights from Mendelian randomization

BACKGROUND

An increasing number of cohort studies have indicated a correlation between lung diseases and esophageal cancer, but the exact causal relationship has not been definitively established. Therefore, the objective of this study is to assess the causal relationship between lung diseases and esophageal cancer.

METHODS

Single-nucleotide polymorphisms (SNPs) related to lung diseases such as asthma, chronic obstructive pulmonary disease (COPD), lung cancer, and idiopathic pulmonary fibrosis (IPF), along with outcomes data on esophageal cancer, were extracted from public genome-wide association studies (GWAS). A two-sample Mendelian randomization (MR) analysis was then performed using publicly available GWAS data to investigate the potential causal relationship. The effect estimates were primarily calculated using the fixed-effects inverse-variance-weighted method.

RESULTS

Totally, 81 SNPs related to asthma among 218,792 participants in GWAS. Based on the primary causal effects model using MR analyses with the inverse variance weighted (IVW) method, asthma was demonstrated a significantly related to the risk of esophageal cancer (OR 1.0006; 95% CI 1.0003-1.0010, p = 0.001), while COPD (OR 1.0306; 95% CI 0.9504-1.1176, p = 0.466), lung cancer (OR 1.0003, 95% CI 0.9998-1.0008, p = 0.305), as well as IPF (OR 0.9999, 95% CI 0.9998-1.0000, p = 0.147), showed no significant correlation with esophageal cancer.

CONCLUSIONS

The two-sample MR analysis conducted in this study revealed a positive causal relationship between asthma and esophageal cancer. In contrast, esophageal cancer demonstrated no significant correlation with COPD, lung cancer, or IPF. Further large-sample prospective studies are needed to validate these findings and to provide appropriate recommendations regarding esophageal cancer screening among patients with asthma.

The immunological and structural epidermal barrier dysfunction and skin microbiome in atopic dermatitis-an update

Atopic dermatitis (AD) is a common, chronic and relapsing inflammatory skin disease with various clinical presentations and combinations of symptoms. The pathophysiology of AD is complex and multifactorial. There are several factors involved in the etiopathogenesis of AD including structural and immunological epidermal barrier defect, imbalance of the skin microbiome, genetic background and environmental factors. Alterations in structural proteins, lipids, proteases, and their inhibitors, lead to the impairment of the stratum corneum which is associated with the increased skin penetration and transepidermal water loss. The elevated serum immunoglobulin E levels and blood eosinophilia have been shown in the majority of AD patients. Type 2 T-helper cell immune pathway with increased expression of interleukin (IL)-4, IL-5, and IL-13, has an important role in the etiopathogenesis of AD. Both T cells and keratinocytes contribute to epidermal barrier impairment in AD via a dynamic interaction of cytokines and chemokines. The skin microbiome is another factor of relevance in the etiopathogenesis of AD. It has been shown that during AD flares, Staphylococcus aureus (S. aureus) colonization increased, while Staphylococcus epidermidis (S. epidermidis) decreased. On the contrary, S. epidermidis and species of Streptococcus, Corynebacterium and Propionibacterium increased during the remision phases. However, it is not clear whether skin dysbiosis is one of the symptoms or one of the causes of AD. There are several therapeutic options, targeting these pathways which play a critical role in the etiopathogenesis of AD. Although topical steroids are the mainstay of the treatment of AD, new biological therapies including IL-4, IL-13, and IL-31 inhibitors, as well as Janus kinase inhibitors (JAKi), increasingly gain more importance with new advances in the therapy of AD. In this review, we summarize the role of immunological and structural epidermal barrier dysfunction, immune abnormalities, impairment of lipids, filaggrin mutation and skin microbiome in the etiopathogenesis of AD, as well as the therapeutic options for AD and their effects on these abnormalities in AD skin.